# lib.umdName

- **Type:** `string`
- **Default:** `undefined`

The export name of the [UMD](/guide/basic/output-format#umd) bundle.

:::tip

The module name of the UMD bundle must not conflict with the global variable name.

:::

## Example

The UMD bundle will be mounted to `global.MyLibrary`.

```ts title="rslib.config.ts" {5}
export default {
  lib: [
    {
      format: 'umd',
      umdName: 'MyLibrary',
    },
  ],
};
```
